STIGQter: STIG Summary: Microsoft Exchange 2016 Edge Transport Server Security Technical Implementation Guide Version: 2 Release: 6 Benchmark Date: 30 Jan 2025:

Exchange internal Send connectors must require encryption.

DISA Rule

SV-221262r961632_rule

Vulnerability Number

V-221262

Group Title

SRG-APP-000439

Rule Version

EX16-ED-000690

Severity

CAT I

CCI(s)

• CCI-002418 - Protect the confidentiality and/or integrity of transmitted information.

Weight

10

Fix Recommendation

Open the Exchange Management Shell and enter the following command:

Set-SendConnector -Identity <'IdentityName'> -TlsDomain <'SMTP Domain'>

Set-SendConnector -Identity <'ReceiveConnector'> -DomainSecureEnabled 'True'

Note: The SMTP Domain is the internal SMTP domain within the organization.

The following commands can be executed if smarthosts are used:

Set-SendConnector <'IdentityName'> -RequireTLS $true -TlsAuthLevel $DomainValidation

Check Contents

Open the Exchange Management Shell and enter the following command:

Get-SendConnector | Select Name, Identity, TlsDomain

If the value of "TlsDomain" is not set to the value of the internal <'SMTP Domain'>, this is a finding.

Get-SendConnector | Select Name, Identity, DomainSecureEnabled

If the value of "DomainSecureEnabled" is not set to "True" and the SendConnector is not using a smarthost, this is a finding.

If the value of "DomainSecureEnabled" is set to "False" and the send connector is using a smarthost, the value of “RequireTLS” must be set to “True”, and the value for “TlsAuthLevel” must be set to “DomainValidation”.

If the send connector using a smarthost has a value for “RequireTLS” that is not set to “True”, this is a finding.

If the send connector using a smarthost has a value for “TlsAuthLevel” that is not set to “DomainValidation”, this is a Finding.

Vulnerability Number

V-221262

Documentable

False

Rule Version

EX16-ED-000690

Severity Override Guidance

Open the Exchange Management Shell and enter the following command:

Get-SendConnector | Select Name, Identity, TlsDomain

If the value of "TlsDomain" is not set to the value of the internal <'SMTP Domain'>, this is a finding.

Get-SendConnector | Select Name, Identity, DomainSecureEnabled

If the value of "DomainSecureEnabled" is not set to "True" and the SendConnector is not using a smarthost, this is a finding.

If the value of "DomainSecureEnabled" is set to "False" and the send connector is using a smarthost, the value of “RequireTLS” must be set to “True”, and the value for “TlsAuthLevel” must be set to “DomainValidation”.

If the send connector using a smarthost has a value for “RequireTLS” that is not set to “True”, this is a finding.

If the send connector using a smarthost has a value for “TlsAuthLevel” that is not set to “DomainValidation”, this is a Finding.

Check Content Reference

M

Target Key

4079